Adjusting apparatus in edging machines



April 23, 1940.

K. E. EVRELL ADJUSTING APPARATUS IN EDGING MACHINES Filed Feb. 19 195")5 Sheets-Sheet 1 April 23, 1940. K. E. EVRELL ADJUSTING APPARATUS INEDGING MACHINES Filed Feb. 19, 1937 3 Sheets-Sheet 2 j 7 M W April 23,1940. K. E. E'VRELL ADJUSTING APPARATUS IN EDGING MACHINES Filed Feb.19, 1937 3 Sheets-Sheet Patented Apr. 23, 1940 ZJtSJM PATENT FriesADJUSTING APPARATUS IN EDGING MACHINES Kaleb Emil Evrell, Eskilstuna,Sweden, assignor to Aktiebolaget Bolinder-Munktell, Eskilstuna, Sweden,a corporation of Sweden Application February 19, 1937, Serial No.126,730 In SWedenIMarch 17, 1936 3 -Glaims.

The edging machine in a sawing plant has for itsobject to trim the roughedges of the wood obtained from the saw frames. The board or plank isadvanced by feed rollers towards two 5 edging blades which areset in adesired distance from each other. For each plank reaching "the edgingmachine the edging operator has to judge the width which may be obtainedtherefrom, set the movable saw-blade in a corresponding position andlock it therein, and push the plank into a position so as to be grippedby the feed rollers. Since the width of the wood varies to a greatextent, and usually, it is important to obtain a maximum of width ofeach plank, practically each plank passing the edging machine requiresits particular width adjustment. It is true that in a present-day easilyoperable edging machine each adjusting operation requires a rather smallamount of work but with the more and more forced working speed which isnow used the physical effort will be very considerable. The shiftingoperations must in fact be performed in a quick succession and rapidlyas possible.

However, considerable difficulties have been met with in rendering theadjustment of the work or saws automatic due to the precisenessrequiredto keep the dimensions of the wood within the narrow limits which arerequired from a point of view of quality. When sawing the wood it isoften rough, often taken directly from the water, and must then be sawedto surplus dimensions gauged so that the sawed Wood afterdrying stillcomes up to the standard in spite of the reductions of dimensionaccompanying the drying. The magnitude of said drying shrinking has beengathered from practice; generally, in northern sawing plants the wood isedged to dimensions about B=1.013 B0+2 mm, where Bois the nominal width.Thus, for a nominal width of 7 inches B=1.0l3-7-25.4+2=l82.1 mm.according to said formula instead of the nominal gauge 177.8 mm. As arule, conventional edging. machines are provided with a locking rodcomprising stop notches spaced 1.013-25.4=25.7 mm. apart from each othercorresponding to 1" of nominal change of dimension. An adjustment ofhalf inches is also used for smaller widths. By an axial adjustment ofsaid rod it is possible to adjust to various additions of dimension butno change of the magnitude of the displacement, i. e. the

distance between the stop notches is, possible.

The present invention has for its object to facilitate the Work ofshifting the saw-blades. In the first place, this is obtained accordingto the invention by an apparatus which isadapted to set the saw-bladesin position by means of an auxiliary power, preferably by a pressuremedium for the generation of the auxiliary power. According to a featureof the invention the apparatus is constructed so as to shut off theauxiliary 5 power when the saw-blades have moved to the desired extent,and according to a further featurewthis shutting-off is effected by theadjusting movement of the saw-blades. The edging operator has only toset an easily movable operl0 ating member in a position whichcorresponds to the desired dimension of width, whereupon the adjustingapparatus driven by auxiliary power effects the displacement of thesaw-blades and the interruption of the adjusting movement auto- 15matically, and keeps the saw-blades in the adjusted position. In theembodiments of the invention described below anoperating slide is set inposition directly or indirectly by the operator but the remaining workfor the adjustment of the saw-blades is eiiected automatically. Themovements of the operating slide correspond to definite adjustingmovements of the saw-blades. The operating slide is completely balancedand thus easily displaceable so as to be easily set in 25 position. Thepressure medium delivering the auxiliary poweracts, according to afurther feature of the invention, upon one or more pistons which areconnected with the saw-blades or a working table carrying said blades insuch a 30 manner that the connecting or transmitting elements are alwaysexposed to constant forces in one direction. By this means any influenceof play and resiliency in said transmitting elements will be eliminatedand the preciseness oi the 35 adjustment will only become dependent uponthe exactness with which an index division. determining the adjustmentpositions of the operating slide is constructed.

The application of the invention is shown by 40 way of example in theaccompanying drawings.

The construction will be cleared more in detail by the accompanyingdrawings.

Fig. 1 is a side elevation of an edging machine having a hydraulicadjusting apparatus according to the invention.

Fig. 2 is a sectional view along the driving shaft thereof and atransverse view of the adjusting mechanism. 50

Figure 3 is a view of one end of the apparatus showing parts in sectionfor the purpose of clearness of illustration. a

Figure 4 is a vertical sectional view taken substantially along the linei-Aof Figure 3 and, 55

Figure 5 is a sectional View taken substantially along the line 55 ofFigure 3.

Both saw-blades I and '2 are driven by a belt on the pulley 3. Theblades are fixed on tubular shafts 4 and 5 respectively the former ofwhich is journalled in the table I displaceable on guides 6, and thelatter in the fixed frame. As usual, the driving power for thedisplaceable blade I is transmitted by a spline shaft 8 axiallydisplaceable in the tubular shaft 5. 3 designates feed rollers of ausual type.

The shifting shaft It carried in the frame is connected with the table'I by levers II and links I2. Keyed to said shaft is a lever I3 having,at the outer end thereof, an adjusting screw I4 forming a stop for thelever which comprises two plates I5 and is provided with an eccentricpin I6 (Fig. 3).

The operating liquid works in two cylinders including a main cylinder I1and an auxiliary cylinder I8 the former of which constitutes a housingfor a slide valve and its associated parts. The auxiliary cylinder I8provides a pressure cylinder in which the piston or the plunger I 9works.

' The plunger I9 is fixed to the working table I and is of largereffective area than the piston 24.

The pressure oil issupplied to the main cylinder I I through the passage20. The main cylinder communicates with the pressure cylinder It by thechannel 2| and the tube 22. The pressure oil is delivered from an oilpump of a conventional type not shown. The cylinder II encloses a doubleslide arrangement consisting of an outer slide or piston 24 and anoperating slide valve 25 disposed in side thereof. The pressure oilenters the chamber 28 below the operating slide through bores 26 and 21(Figs. 3 and 4). Said chamber as well as the cylinder chamber 29 abovethe piston 24 has thus a pressure above the atmospheric. Two portions ofthe piston 24 are cut away to form grooves 30 and 3| the former of whichcommunicates constantly with the pressure cylinder I8 by the passage 2Iand the tube 22, and the latter communicates constantly with the returnconduit or exhaust by the passage 23. The grooves 30 and 3| communicatewith the inner bore of the piston 24 by ports 32 and 33. The annulargroove or reduced portion 34 which is constantly pressure-free due tothe connection with the return conduit over the groove Ill and thepassage 23 serves to release the packing 35 from any oil pressure. Alsothe packing, 36 for the plunger I9 is released in a similar manner fromthe oil pressure by the cuttingout 37 which communicates with the returnconduit by a tube.

The oil pressure acts constantly on the outer slide 24 by a forcewherein p is the oil pressure per unit of area and D the inner diameterof the slide housing. Said force is transmitted to the table .I- by thelink 38, pin I6, shaft I I], levers II and links I2. In order to obtainuniform movements of the table I and the outer slide 24 the lengths ofthe links I2 and 38 are made proportional to the lengths L and Z of thelevers and further the positions of the pins are made such that in eachposition of the table I the angle between the centre lines of the linkI2 and the lever II is approximately equal to the corresponding angle ofthe link 38 and lever I5.

The force which tends to carry the table I be inserted: p1= /2 p.

and the blade I from the left to the right (Figs. 2 and 3) is wherein mis the pressure above atmospheric of the oil in the pressure cylinder I8and p is the pressure above atmospheric of the oil in the slide housingII. p is equal to the available work pressure, 121 being able to varybetween 1; and 0 as will be shown in the following.

As shown in Fig. 3, d and D are the diameters of the pistons I9 and. 24respectively, and l and L are the effective lengths of the levers i5 andII respectively.

Pmin is apparently negative, that is a force of the magnitude Thediameters and leverage are chosen so as to approximately satisfy saidformula. The condition that P is equal tonaught, that is that theforcesacting on the table I' would balance each other is obtained from theformula:

The shifting movements will be obtained by varying the pressure in thecylinder I8 in an adequate manner. I

The operating slide value 25 is displaced by means of the'handle 39 onthe double lever 40 from which the movement is transmitted by the rod4|, lever 42, shaft 43 and toothed segment 44 to the extension 45 of theoperating slide 25 constructed as a toothed rack, Figs. 1' and 3.

The toothed rack 45 has also a series of grooves or index 41 in whichthe spring-loaded pawl 46 may engage. All surfaces of the operatingslide valve 25 and its extension 45 except those which are adjacent tothe annular chamber 48 are always exposed to the pressure p. Thus theoil pressure cannot displace said slide but it is completely balanced.Should the handletil be displaced from the position shown in Fig. 1 soas to move the slide valve 25 to an extent 5 so as to reach the nextgroove for the pawl, communication is established between the chambers28 and 30 by the fact that the lower part 49 of the operating slide 25uncovers the passage 32 in the piston 24. I The pressure oil from thechamber 29 is now free to flow to the pressure cylinder I8 through theholes 26 and 21, passage 32, chamby the passage 33.

right (the space between the blades I and 2 decreases); Due to theconnection of the table 1 and the piston 24 over the shaft Hi, thepiston is compelled tobe pushed upwards by said movement. When thepiston has now moved to an extent a, that is to the same extent as theoperating slide had been displaced, the passage 32 will be covered againby the portion 49 of the operating slide. The axial length of theportion 49 is made slightly (0.1 to 0.2 mm.) smaller than the axialdimension of the passage 32. quently, said passage is never closedcompletely by the portion 49 of the operating slide but the wholearrangement will act as a strong restriction of the connection from thechamber 28 over the port 32 to the chamber 48. The operating pressure pexists in the chamber 28, and in the chamber 3!] the same pressure ispresent as in the working cylinder l8 with which it communicates, thatis a pressure which was previously designated by 101, whereas nopressure above atmospheric exists in the chamber 48 which communicatesconstantly with the outlet conduit 23 As shown above the .forces fromthe piston 24 and the piston l9 balance each other when p1= p.Equilibrium will thus occur when the portion 49 has been adjusted tosuch a position in relation to the port 32 that the pressure drop fromthe chamber 28 to the passage 32 is equal to the pressure drop from thesame passage to the chamber 48 The piston 24 has moved to exactly thesame,

extent 6 as the operating slide valve 25 when the forces balance eachother. This movement corresponds to a movement of the table of and thespace 6 between the index grooves 4'! is to be chosen with regard to theratio so that correct intervals of displacement are obtained.

Should the slide valve be displaced downwards instead of upwards, theslide portion 49 will uncover the port 32 so as to establish acommunication between the pressure cylinder l8 and outlet 23. Thepressure n then becomes naught and the table 1 moves to the left. Aftersuch 7 Said pointer moves along a graduated scale 5| which is graduatedin the nominal widths for which the edging machine is adapted. The scale55 is only adapted for an approximate adjustment whereas the fineadjustment is efiected automatically by the pawl 46 as soon as thehandle lever has carried the slide 25 in the proximity of the desiredposition.

As hereinbefore shown the intervals of displacement of the table 1 is tand L are constant measures whereas the lever lengths Z may be changedby turning the eccen- Conse- I tric bolt 16. By screwing the adjustingscrew 14 when the oil pressure in the system holds the piston 24 in acertain fixed position of the oper-- ating slidevalve 25 the table 1 isdisplaced without changing the operating slide. The beforementionedformula B=1.013 Bo+2 for widths to which the raw wood is edged may alsobe Written B=B'o-:-mBo+'n, wherein B is the desired width of wood withadded drying measure, Bo nominal width of wood and m and n constantquantities. The constant quantity m is changed by turning the eccentricbolt l6, that is the percentage of surplus is varied thereby, and byadjusting the adjustmentscrew I4 the constant quantity n is varied,which is the same as an amendment of the constant addition to the widthThese both adjustment possibilities serveto eliminate faults ofconstruction in the edging machine itself and give at the same timeconvenient possibility for each individual edging machine owner to setthe surplus on values which suit for his type of wood.

It will be seen that the piston 24 is acted upon at all times by thepressure liquidor medium in the chamber 29. of the piston 24 with thetable I through the lever mechanism, the force exerted by the piston24'underthe action of the pressure thereon is sufiicient to move thetable when the plunger cylinder I8 is opened to the exhaust 23 by thevalve 25, but is insufiicient to oppose the force of the plunger I9 whenthe valve is moved so that the plunger is acted on by the pressure fluidin the chamber 28. In other words, the initial movement of the valve 25to position theenlarged portion 49 thereof either below or above theport 32, will determine whether or not the table is to be moved in onedirection by the plunger l9 or in an opposite direction by the,

piston 24. Further, the lever connection of the Due to the connectionpiston with the table or movable member 1 provides automaticallyoperable means for displacing the piston to a position corresponding tothat which the valve has been set and the pawl 46 insures the partsbeingmaintained in theiradjusted positions until the lever 39 is againactuated.

It will be understood that the form of the invention shown and describedis illustrative of a preferred embodiment and that such changes may bemade as fall within the purview of one skilled in the art, withoutdeparting from the spirit of the invention and the scope of the appendedclaims.

What I claim is V 1. In a machine of the class described, thecombination of a movable member, means for adjusting and maintaining themovable member in a predetermined position, said means including a maincylinder and an auxiliary cylinder, means for introducing a pressuremedium into the main cylinder, a pressure actuated piston in the maincylinder, a lever mechanism connecting the piston to the movable memberto move the latter in one direction, said main cylinder having anexhaust port therein, a pressure actuated plunger in the auxiliarycylinder, said plunger being of larger efiective area than the piston,means connecting the plunger to the movable member to move the same inan opposite direction, said piston having a bore provided with'apressure chamber, means for communicating the pressure chamber with theauxiliary cylinder, means for communicating the auxiliary cylinder withthe exhaust port, valve means for selectively controlling thecommunication of the auxiliary cylinder with the pressure chamber andthe exhaust port, means for conducting the pressure medium from the maincylinder to the pressure chamber, and manually operable means forinitially setting the valve independently of the movable member to itspredetermined position, said piston being acted upon bythe pressure me-.dium in the main cylinder at all times so that the force exerted on thepiston under the action of the pressure thereon is sufiicient to movethe movable member when the auxiliary cylinder is open to the exhaustport by the valve but insufficient to oppose the force of said plungerwhen the valve is moved to establish the flow of the pressure mediumfrom the pressure chamber to the auxiliary cylinder, the connection ofsaid piston with the movable member arranged automatically to displacethe piston to a position corresponding to thatwhich the valve has beenset.

'2. In a machine of the class described, the combination of a movablemember, means for effecting relative adjustment of said member, saidmeans including a main cylinder and an auxiliary cylinder, means forintroducing a pressure medium into the main cylinder, a pressureactuated piston in the main'cylinder, a pressure actuated plunger in theauxiliary cylinder, said plunger being of larger effective area than thepiston, means connecting said plunger to the movable member, a levermechanism connecting said piston to the movable member, said maincylinder having an exhaust port, said piston having a bore provided witha pressure chamber, the wall of said bore having spaced openings, one ofsaid openingsestablishing'communication of the pressure chamber with theauxiliary cylinder and the other of said openings arranged tocommunicate the auxiliary cylinder with the exhaust port, a valveassociated with said openings and selectively operable to control communication of the auxiliary cylinder with the pressure cylinder and theexhaust, port, and means for initially setting the valve independentlyof the movable member to its predetermined position, said piston beingacted upon by the pressure medium in the main cylinder at all times sothat the force exertedon the piston under the action of the pressurethereon is sufiicient to move the movable member when the auxiliarycylinder is open to the exhaust port by the valve, but insufficient tooppose the force of said fecting relative adjustment of said member,said means including a main cylinder and an auxiliary cylinder, apressure actuated piston in the main cylinder, a levermechanismconnecting said piston to the movable member, a pressureactuated plunger in the auxiliary cylinder, said plunger being of largerefiective area than the piston, means connecting said plunger to themovable member, said main cylinder having an exhaust port, said pistonhaving a bore provided with a pressure cylinder, the wall of said maincylinder coacting with one side of said piston to provide a passage,means communicating said passage with the auxiliary cylinder, the wallof said pistonhaving axially spaced openings, one of said openingscommunicating said passage with the pressure chamber, the opposite sideof said piston coacting with the adjacent wall of said cylinder toprovide a second passage communicating with the exhaust port, the otherof said openings communicating the second passage with the bore of saidpiston, a slide valve extending into the bore of the piston forcontrolling said spaced openings and operable selectively to controlcommunication of the auxiliary cylinder with the pressure cylinder andtheexhaust port, and means for initially setting the valve independentlyof the movable member to its predetermined position, said piston beingacted upon by the pressure medium in the main cylinder at all times sothat the force exerted on the piston under the action of the pressuremedium thereon is sufficient to actuate the movable member when theauxiliary cylinder is open to the exhaust port by the valve, butinsufiicient to oppose the force of said plunger when the valve is movedto establish the flow of the pressure medium to the auxiliary cylinder.

KALEB EMIL EVRELL.

